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NVAP Reference Guide: Tuberculosis

(Control and Eradication)

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NVAP Reference Guide: Table of Contents

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Preface

Introduction

Control and Eradication

Brucellosis

Johne’s Disease

Pseudorabies (PRV)

Tuberculosis

Transmissible Spongiform Encephalopathies

Scrapie

Bovine Spongiform Encephalopathy (BSE)

Chronic Wasting Disease (CWD)

Poultry
National Poultry Improvement Plan (NPIP)

Avian Influenza (AI)

Exotic Newcastle disease (END)

Equine Disease

Aquatic Animal

Aquatic Animal National Health Plan

Aquatic Animal Health Activities

Animal Health Emergency Management

Animal Health Emergency Management

Emergency Response Structure

National Response Framework (NRF)

National Incident Management System (NIMS)

National Animal Health Emergency Management System (NAHEMS)

Foreign Animal Disease Preparedness and Response Plan (FAD PReP)

FAD Recognition and Initial Response

National Animal Health Emergency Response Corps (NAHERC)

Notifiable Diseases and Conditions

WOAH and International Standards

Cleaning and Disinfection

Importance of Cleaning & Disinfection

Cleaning

Disinfection

Regulation of Disinfectants

Safety

Disease Surveillance

Laboratory Submissions

Animal Movement

Interstate Regulations

Interstate Movement of Cattle, Horses, Swine, Sheep and Goats

Issuing Interstate Animal Movement Documents

International Animal Movement

Issuing International Health Certificates (IHCs) for Live Animal Movement

Common Problems Observed on Certificates for Live Animal Movement
Animal Identification 

Animal Identification

Cattle Identification

Swine Identification

Equine Identification

Sheep and Goat Identification

Fowl Identification

Compliance and Regulations

Appendix

A: 9 CFR PARTS 160, 161, and 162

B: APHIS VS District Offices

C: State Animal Health Officials

D: Forms

E: Other Organizational Information with Contact Points

F: Web Sites

G: Equine Teeth and Aging

Bovine tuberculosis (TB) is a contagious, infectious, communicable disease of

animals and humans caused by Mycobacterium bovis. It is commonly a chronic,

debilitating disease but occasionally may assume an acute, rapidly progressive

course. TB is a widespread zoonosis of global magnitude and affects nearly all

species of vertebrates.

Disease is spread by direct contact, inhalation of droplets expelled from infected

lungs, and ingestion of contaminated feed or milk. All accredited veterinarians must

immediately report every suspected or diagnosed bovine TB case promptly to both

the Assistant District Director and the State Animal Health Official.

Testing

Diagnosing TB in live animals depends on using an effective testing technique with

an intradermal injection of tuberculin obtained through your State animal health
official or APHIS –VS Area Offices. Several varieties of tuberculin are produced.

However, use only bovine purified protein derivative tuberculin (PPD bovis) licensed

by USDA for official testing. See table 1 for tuberculin test requirements for different

species of animals.

Table 1 – Tuberculin test information for various animal species

Species Dose and

Type

Site Read test visually and

palpate

Cattle & Bison 0.1 mL PPD

bovis Caudal Fold 72 h +/- 6h

Horses Not reliable

Sheep & Goats 0.1mL PPD

bovis Caudal Fold 72 h

Swine 0.1mL PPD

bovis

Base of Ear or Vulvar

lips 48 h

Poultry 0.05 mL avian Wattle 48 h

Exotic Bovidae 0.1mL PPD

bovis Midcervical 72 h

Deer, Elk &

other

Cervidae

0.1mL PPD

bovis Midcervical 72 h

Camelidae 0.1mL PPD

bovis Postaxillary Region 72 h

Note: TB testing and test result interpretation for many exotic species (such as

some zoo animals) are not yet developed or reliable. For interstate movement of

these animals, contact the State animal health official in the State of destination for

the TB-testing requirements (if any) for these species.

Because the tuberculin test is based on an immune response, the animal being

tested should not concurrently be receiving other medications, vaccinations, or

anthelminthic drugs. These agents may temporarily affect the immune system and

influence the result of the tuberculin test. This also means that sick animals may not

be injected even if they are not being medicated or treated in any fashion. In

addition, tail-bleeding is not recommended for other diagnostic procedures (e.g.,
brucellosis, Johne’s disease) at the time of tuberculin-test injection in cattle or bison

because tail-bleeding may interfere with test interpretation.

Veterinarians are legally responsible for properly conducting and evaluating the

results of tuberculin tests. Therefore, perform the test yourself; do not delegate the

responsibility to a technician. For TB testing in species other than cattle or bison

(e.g., cervidae), contact your State animal health official or APHIS –VS Area Offices

for additional guidance.

Instructions for Testing

Step 1: Forms

1. Complete VS Form 6–22, Tuberculosis Test Record. (See Appendix D for an

example of VS Form 6-22 Tuberculosis Test Record and instructions for

completing it)

2. Identify the animal on the form by its official identification as outlined in the

section entitled “Current Animal Identification.”

All cattle and bison tested shall be individually identified by official eartags.

Such identification must be recorded in its entirety on the test record at the

time of injection and must be confirmed at the time of observation.

Additional identification (such as bangle tags, non-official metal ear tags, neck

chain numbers, tags, brands, horn numbers, and names) should also be

recorded on the test record as supplemental information, but must never be

used as the sole method of identification.

When cattle and bison have been tagged with more than one official ear tag, all

ear tag numbers must be recorded in their entirety.

The breed, sex, and approximate age in years of each animal tested must be

recorded in their entirety on the test record. Abbreviations such as C=Calf or

A=Adult are not to be used.

The owner should be informed of the number of animals injected, and advised

to restrict them to the premises until the test is completed.

Step 2: Supplies

1. Tuberculin. Use USDA-Veterinary Services approved PPD Bovis tuberculin (see

table 1). Check the expiration date to be certain that the tuberculin is still valid.
2. Syringe. Use disposable 1.0 cc plastic tuberculin syringe.

3. Needle. Use a 26-gauge, 3/8-inch-long needle; a larger gauge and longer or

shorter needle might allow the tuberculin to leak from the injection site. A new

needle must be used for each animal. 

Step 3: Injection of Tuberculin

All cattle and bison tested must be sufficiently restrained to permit careful

application of the tuberculin injection(s), correct reading of animal identification, and

careful observation and palpation of the injection sites. No test should be applied or

observed without having the animal restrained in a satisfactory manner. Nose tongs

are no longer used by APHIS regulatory personnel.

1. In cattle and bison, injections should be made about 2 to 3 inches distal to the

base of the tail. Rest the caudal fold on the forefinger exposing the area outside

the hairline in bare skin near the center of the caudal fold.

2. Note scars, defects, and anomalies of the skin in this area on VS Form 6–22 so

that they will not be confused with possible test reactions at the time of

reading.

3. Use the caudal fold on either side of the tail; however, note which side you

injected.

4. Clean the area to be injected, but do not use alcohol because it may be

irritating to the skin.

5. Grasp the caudal fold between the thumb and index and middle fingers to

stabilize it.

6. Carefully insert the needle to its full length between the superficial layers of the

skin; withdraw it slightly and deposit 0.1 mL of tuberculin.

7. A small bleb should appear in the skin at the end of the needle.

Note: It is important to establish a consistent injection technique (i.e., all animals

should be injected on the same side of the tail)—particularly when testing large

numbers of animals, unless there is some physical abnormality at the injection site.

Step 4: Reading the Test

1. The test must be read between 66 and 78 hours after injection (72 hours is

optimum). The veterinarian who made the injection must be the veterinarian

who reads the test result. Exceptions must be approved in writing by the USDA,
Veterinary Services, Assistant District Director. The veterinarian must

determine the results of the test by both observation and palpation of the

injection site.

2. Verify the identification of the restrained animal and raise the tail to exert slight

tension on the caudal fold.

3. Visually inspect the injection site closely and palpate it carefully to detect

changes from the normal. Any swelling, sensitivity, or increase in thickness of

the skin is considered to be a positive response to the tuberculin. The size of

responses may vary and are not indicative of infectious status. Responses may

be small, hard, pea-sized responses, diffuse responses, circumscribed

responses, or large responses. If there is doubt about whether a response  has

occurred, palpate the opposite side of the tail to determine if there is a change

from normal. Any observed change should be recorded.

4. Test observation without palpation is unacceptable.

Step 5: Recording the Results of the Test

1. Use VS Form 6–22.

2. Enter “N” (negative) when you observe no change in the tissue at the site of

injection.

3. Enter “S” (suspect) when you observe or palpate any increase in caudal fold

thickness, size, or sensitivity, at the injection site as described above.

Reactions and Interpreting Test Results

If an animal is exposed to the antigens present in bovine TB, a tuberculin injection

results in a delayed hypersensitivity reaction manifested by swelling and induration

at the injection site. A positive response usually begins within 8 to 12 hours and

peaks about 72 hours after injection.

If the test produces any type of response, immediately notify your APHIS –VS Area

Offices and State animal health officials. The caudal-fold test is used as a

presumptive diagnostic procedure, and animals classified as suspect must be

evaluated further by the comparative cervical (CC) test, gamma interferon test, or

sent directly to slaughter under permit.

Only Federal or State regulatory veterinarians who have had specialized training

may conduct the follow up testing. Follow-up CCT testing must be performed within
10 days of the initial caudal-fold injection in cattle and bison, or the herd owner must

wait 60 days (90 days for cervidae) after the injection of the CFT before a follow-up

CCT can be administered. If the gamma interferon test is used as a follow up test the

blood must be drawn within 30 days of the CFT inject date. Note: The gamma

interferon test is not approved for use in Bison or captive cervidae. If the CCT or

gamma interferon test indicates that the animal is a reactor, all further herd testing

is conducted by Federal or State regulatory veterinarians.

Accredited veterinarians and regulatory veterinarians are expected to meet the

caudal fold response rates as identified in the 2005 Bovine TB Eradication Uniform

Methods and Rules, Appendix C. Improper injection or observation techniques,

mishandling of tuberculin, and other events may lead to inaccuracies in the test and

true disease status may be missed. See the Bovine TB Eradication Uniform Methods

and Rules for more information. The most current version of this VS-published

document is available on the APHIS website.

9 CFR part 77.1 Material incorporated by reference.

Uniform Methods and Rules—Bovine Tuberculosis Eradication. The Uniform Methods

and Rules—Bovine Tuberculosis Eradication (January 22, 1999, edition) has been

approved for incorporation by reference into the Code of Federal Regulations by the

Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part

51.

(a) The procedures specified in the Uniform Methods and Rules—Bovine Tuberculosis

Eradication (January 22, 1999, edition) must be followed for the interstate

movement of certain animals regulated under this part.